Infrared Spectroscopic Method for Estimating Physical Properties of Metaphosphate Glasses

Calcium metaphosphate glass has been dehydroxylated under vacuum and by calcium fluoride addition. The first overtone band of Vss(OPO) and/or combinational band of Vas(OPO)+Vas(POP) at around 2170 cm^-1 in the infrared (IR) spectra of the glasses, not originally observed in high hydroxyl (OH) containing glasses, has been found to develop gradually with the progress of dehydroxylation. The absorption coefficient of this band has been statistically correlated with density, refractive index and glass transition temperature of low OH containing glasses in the form of equations. Each of these equations has high correlation coefficient and low residual standard deviation. Thus, they have been employed for the estimation of physical properties of high OH containing glasses. The experimental values of the properties of these glasses present a good fit with the calculated mean values within 95 % confidence interval. This fact confirms the validity and utility of this IR spectroscopic approach for the estimation of physical properties of calcium metaphosphate glasses.